Currently, cancer is one of the diseases with the highest mortality rates worldwide. Whereas the age of cancer occurrence is decreased, the average life expectancy is gradually increased, and therefore, the incidence rate of cancer is predicted to increase even more. According to the Statistics in 2013 provided by the National Cancer Center of Korea (Status based on Statistics (Cancer Facts & Figures 2013), p. 18, 2013), the number of cancer patients registered with the Cancer Registry Statistics Division in Korea in 2010 was 202,053, and it was estimated to reach about 270 thousand in 2015.
On the other hand, lignan compounds, which collectively refer to substances formed by two molecules of n-phenylpropane by oxidative condensation, are substances that have a β, γ-dibenzylbutane structure as a basic frame. Lignan is known to be present in higher plants, such as whole grains, legumes, vegetables, fruits, and seeds, etc., in high concentrations in nature, and present in body fluids of animals including humans (Namba, T., Coloured Ilustration of Wakan-Yaku, Hoikusha Publishing, Osaka, 1980, Vol. II, 127-129; Tang, W and G. Eisenbrand, Chinese Drugs of Plant Origin, Springer-Verlag, Berlin, 1992, 639-646).
The research on the effects of lignan compounds has been conducted for a long time, and the effects of the lignan compound that have recently received attention may be antioxidant activities, anti-asthmatic effects, anti-inflammatory effects, etc. (Korean Patent Application Publication No. 10-1999-0035470; Sang-Hyun Lee, et al., Archives of Pharmacal Research, 2004, 27(2), 106-110). However, the research on the anticancer effects of lignan compounds are still insufficient, and specifically, the anticancer effects of lignan compounds having a specific chemical structure are hardly known.
Although lignan compounds have β, γ-dibenzylbutane as a basic frame, lignan compounds fall into quite a broad range, in which the compounds having a wide variety of structures according to substitution, addition, etc., are present. Therefore, lignan compounds inevitably show substantial differences in their properties according to their specific structures. Accordingly, the research on the property of the lignan compounds having specific structures is of utmost significance. In particular, the fact that some of the compounds with fatal toxicity, such as podophyllotoxin, also belong to lignin compounds supports the significance of the study.